Problems with weird edges after Subdviding/Smoothing surface
Ur Problem is the face orientation. If u Turn on &quot;Face Orientation&quot; on and check, u can clearly see half of ur face is its back facing outside (Red is the back of the face, Blue is the front of the face. Generally, u shoud have all faces blue)

select all ur faces and type F3, search for &quot;recalculate outside&quot; to correct ur wrong facing direction. then it should smooth properly